Method apply_sentinels_config!
has a Cognitive Complexity of 11 (exceeds 5 allowed). Consider refactoring. Open
def apply_sentinels_config!(config)
sentinels = config.delete(:sentinels).presence
return unless sentinels
sentinel_user = nil
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Cognitive Complexity
Cognitive Complexity is a measure of how difficult a unit of code is to intuitively understand. Unlike Cyclomatic Complexity, which determines how difficult your code will be to test, Cognitive Complexity tells you how difficult your code will be to read and comprehend.
A method's cognitive complexity is based on a few simple rules:
- Code is not considered more complex when it uses shorthand that the language provides for collapsing multiple statements into one
- Code is considered more complex for each "break in the linear flow of the code"
- Code is considered more complex when "flow breaking structures are nested"
Further reading
ThreeScale::RedisConfig#initialize is controlled by argument 'redis_config' Wontfix
raw_config = (redis_config || {}).deep_symbolize_keys
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Control Parameter
is a special case of Control Couple
Example
A simple example would be the "quoted" parameter in the following method:
def write(quoted)
if quoted
write_quoted @value
else
write_unquoted @value
end
end
Fixing those problems is out of the scope of this document but an easy solution could be to remove the "write" method alltogether and to move the calls to "writequoted" / "writeunquoted" in the initial caller of "write".
ThreeScale::RedisConfig#initialize refers to 'raw_config' more than self (maybe move it to another class?) Open
raw_config.delete_if { |_key, value| value.blank? }
uri = URI.parse(raw_config[:url].to_s)
raw_config[:db] ||= uri.path[1..]
raw_config[:ssl] ||= true if uri.scheme == 'rediss'
apply_sentinels_config!(raw_config)
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Feature Envy occurs when a code fragment references another object more often than it references itself, or when several clients do the same series of manipulations on a particular type of object.
Feature Envy reduces the code's ability to communicate intent: code that "belongs" on one class but which is located in another can be hard to find, and may upset the "System of Names" in the host class.
Feature Envy also affects the design's flexibility: A code fragment that is in the wrong class creates couplings that may not be natural within the application's domain, and creates a loss of cohesion in the unwilling host class.
Feature Envy often arises because it must manipulate other objects (usually its arguments) to get them into a useful form, and one force preventing them (the arguments) doing this themselves is that the common knowledge lives outside the arguments, or the arguments are of too basic a type to justify extending that type. Therefore there must be something which 'knows' about the contents or purposes of the arguments. That thing would have to be more than just a basic type, because the basic types are either containers which don't know about their contents, or they are single objects which can't capture their relationship with their fellows of the same type. So, this thing with the extra knowledge should be reified into a class, and the utility method will most likely belong there.
Example
Running Reek on:
class Warehouse
def sale_price(item)
(item.price - item.rebate) * @vat
end
end
would report:
Warehouse#total_price refers to item more than self (FeatureEnvy)
since this:
(item.price - item.rebate)
belongs to the Item class, not the Warehouse.
ThreeScale::RedisConfig#apply_sentinels_config! has approx 14 statements Open
def apply_sentinels_config!(config)
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A method with Too Many Statements
is any method that has a large number of lines.
Too Many Statements
warns about any method that has more than 5 statements. Reek's smell detector for Too Many Statements
counts +1 for every simple statement in a method and +1 for every statement within a control structure (if
, else
, case
, when
, for
, while
, until
, begin
, rescue
) but it doesn't count the control structure itself.
So the following method would score +6 in Reek's statement-counting algorithm:
def parse(arg, argv, &error)
if !(val = arg) and (argv.empty? or /\A-/ =~ (val = argv[0]))
return nil, block, nil # +1
end
opt = (val = parse_arg(val, &error))[1] # +2
val = conv_arg(*val) # +3
if opt and !arg
argv.shift # +4
else
val[0] = nil # +5
end
val # +6
end
(You might argue that the two assigments within the first @if@ should count as statements, and that perhaps the nested assignment should count as +2.)
ThreeScale::RedisConfig#respond_to_missing? manually dispatches method call Wontfix
super || config.respond_to?(method_sym)
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Reek reports a Manual Dispatch smell if it finds source code that manually checks whether an object responds to a method before that method is called. Manual dispatch is a type of Simulated Polymorphism which leads to code that is harder to reason about, debug, and refactor.
Example
class MyManualDispatcher
attr_reader :foo
def initialize(foo)
@foo = foo
end
def call
foo.bar if foo.respond_to?(:bar)
end
end
Reek would emit the following warning:
test.rb -- 1 warning:
[9]: MyManualDispatcher manually dispatches method call (ManualDispatch)
ThreeScale::RedisConfig#method_missing manually dispatches method call Wontfix
if config.respond_to?(method_sym)
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Reek reports a Manual Dispatch smell if it finds source code that manually checks whether an object responds to a method before that method is called. Manual dispatch is a type of Simulated Polymorphism which leads to code that is harder to reason about, debug, and refactor.
Example
class MyManualDispatcher
attr_reader :foo
def initialize(foo)
@foo = foo
end
def call
foo.bar if foo.respond_to?(:bar)
end
end
Reek would emit the following warning:
test.rb -- 1 warning:
[9]: MyManualDispatcher manually dispatches method call (ManualDispatch)
ThreeScale::RedisConfig has missing safe method 'apply_sentinels_config!' Open
def apply_sentinels_config!(config)
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A candidate method for the Missing Safe Method
smell are methods whose names end with an exclamation mark.
An exclamation mark in method names means (the explanation below is taken from here ):
The ! in method names that end with ! means, “This method is dangerous”—or, more precisely, this method is the “dangerous” version of an otherwise equivalent method, with the same name minus the !. “Danger” is relative; the ! doesn’t mean anything at all unless the method name it’s in corresponds to a similar but bang-less method name. So, for example, gsub! is the dangerous version of gsub. exit! is the dangerous version of exit. flatten! is the dangerous version of flatten. And so forth.
Such a method is called Missing Safe Method
if and only if her non-bang version does not exist and this method is reported as a smell.
Example
Given
class C
def foo; end
def foo!; end
def bar!; end
end
Reek would report bar!
as Missing Safe Method
smell but not foo!
.
Reek reports this smell only in a class context, not in a module context in order to allow perfectly legit code like this:
class Parent
def foo; end
end
module Dangerous
def foo!; end
end
class Son < Parent
include Dangerous
end
class Daughter < Parent
end
In this example, Reek would not report the Missing Safe Method
smell for the method foo
of the Dangerous
module.